Re: [Qemu-devel] [PATCH COLO-Frame v12 11/38] COLO: Add a new RunState RUN_STATE_COLO

[Markus Armbruster]

zhanghailiang <address@hidden> writes:

> Guest will enter this state when paused to save/restore VM state
> under colo checkpoint.
>
> Cc: Eric Blake <address@hidden>
> Cc: Markus Armbruster <address@hidden>
> Signed-off-by: zhanghailiang <address@hidden>
> Signed-off-by: Li Zhijian <address@hidden>
> Signed-off-by: Gonglei <address@hidden>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>
> Reviewed-by: Eric Blake <address@hidden>
> ---
>  qapi-schema.json | 5 ++++-
>  vl.c             | 8 ++++++++
>  2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 85f7800..0423b47 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -154,12 +154,15 @@
>  # @watchdog: the watchdog action is configured to pause and has been 
> triggered
>  #
>  # @guest-panicked: guest has been panicked as a result of guest OS panic
> +#
> +# @colo: guest is paused to save/restore VM state under colo checkpoint 
> (since
> +# 2.6)
>  ##
>  { 'enum': 'RunState',
>    'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
>              'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
>              'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
> -            'guest-panicked' ] }
> +            'guest-panicked', 'colo' ] }
>  
>  ##
>  # @StatusInfo:
> diff --git a/vl.c b/vl.c
> index f84fde8..fca630b 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -594,6 +594,7 @@ static const RunStateTransition 
> runstate_transitions_def[] = {
>      { RUN_STATE_INMIGRATE, RUN_STATE_WATCHDOG },
>      { RUN_STATE_INMIGRATE, RUN_STATE_GUEST_PANICKED },
>      { RUN_STATE_INMIGRATE, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_INMIGRATE, RUN_STATE_COLO },
>  
>      { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PAUSED },
>      { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },
> @@ -603,6 +604,7 @@ static const RunStateTransition 
> runstate_transitions_def[] = {
>  
>      { RUN_STATE_PAUSED, RUN_STATE_RUNNING },
>      { RUN_STATE_PAUSED, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_PAUSED, RUN_STATE_COLO},
>  
>      { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
>      { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },
> @@ -613,9 +615,12 @@ static const RunStateTransition 
> runstate_transitions_def[] = {
>  
>      { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
>      { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
> +    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_COLO},
>  
>      { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
>  
> +    { RUN_STATE_COLO, RUN_STATE_RUNNING },
> +
>      { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
>      { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
>      { RUN_STATE_RUNNING, RUN_STATE_IO_ERROR },
> @@ -626,6 +631,7 @@ static const RunStateTransition 
> runstate_transitions_def[] = {
>      { RUN_STATE_RUNNING, RUN_STATE_SHUTDOWN },
>      { RUN_STATE_RUNNING, RUN_STATE_WATCHDOG },
>      { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },
> +    { RUN_STATE_RUNNING, RUN_STATE_COLO},
>  
>      { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
>  
> @@ -636,9 +642,11 @@ static const RunStateTransition 
> runstate_transitions_def[] = {
>      { RUN_STATE_RUNNING, RUN_STATE_SUSPENDED },
>      { RUN_STATE_SUSPENDED, RUN_STATE_RUNNING },
>      { RUN_STATE_SUSPENDED, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_SUSPENDED, RUN_STATE_COLO},
>  
>      { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
>      { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_WATCHDOG, RUN_STATE_COLO},
>  
>      { RUN_STATE_GUEST_PANICKED, RUN_STATE_RUNNING },
>      { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },

Pardon my ignorance, but could you explain the new run state in a bit
more detail for me?

Your additions to runstate_transitions_def[] show we can go *from* state
'colo' only to state 'running', but we can go *to* state 'colo' from
various other states.  This may well be sane, but it's not *obviously*
sane :)